It is known to use arrays of light-emitting diodes (LEDs), mounted on printed circuit boards, for lighting purposes. For instance in lighted advertising, such as backlighted letters, plastic backlighting, and so forth; in safety lighting, such as escape route lighting, orientation lighting, marking lighting systems; and in lighting systems for motor vehicles, it is known, instead of conventional incandescent bulbs or gas discharge bulbs, to use LEDs, which have a longer service life, better efficiency in converting electrical energy into radiation energy in the visible spectral range, and associated with it a lesser power loss and a lesser requirement for space. Particularly in lighted advertising, the high flexibility in terms of geometrical shaping and the versatility of coloring that LEDs offer has great significance.
In German Utility Model DE 298 18 609 U1, an array of circuit boards for arbitrarily setting up LED lighting units is disclosed, in which many circuit boards are provided that carry light-emitting diodes and that cohere superficially, are embodied polygonally, and are joined together by webs. From this matrix-like array of circuit boards, an arbitrary number or partial quantity of the LED-carrying circuit boards can be broken out, resulting in partial quantities that have versatile design options in terms of the geometrical dimensions.
In International Patent Disclosure WO 99/41785, an LED light panel that can be preassembled is disclosed. It includes a number of LED chips, onto each of which an optically transparent protective layer is applied. The light panel can be broken apart into subsidiary units.
Normally, light-emitting diodes have an essentially point-shaped light source, which has a conical beam with an opening angle of 120° for instance.